The above-mentioned type of processes for producing detergents have the purpose of manufacturing a rational and environmentally beneficial detergent in one working step. The detergent made in this manner can be applied by the user without any negative effect. One such negative effect is present if the formaldehyde escaping from urea-formaldehyde resin foam and used in manufacture gets into the air during cleaning. Processes are known to prevent this from happening wherein the free formaldehyde from the urea-formaldehyde resin foam is reduced by means of a subsequent addition of formaldehyde binding agents.
Accordingly, German published patent application No. DE-OS 29 17 064 discloses, for example, a process for reducing the development of formaldehyde from amino-plastic foam material wherein the finished foam material is surface treated with a formaldehyde binding agent which is essentially non-volatile and which draws moisture. In this connection, the formaldehyde binding agent should be an aqueous solution of urea or a salt of the sulfuric acids as well as an aqueous mixture of urea, ammonia, ammonium sulfite and an agent for holding water or an agent for attracting water.
In methods of the above-mentioned type, it is disadvantageous that these agents must be added subsequently to the foam substance or the amino-plastic carrier material; this especially involves a further process step. Furthermore, it has been shown to be disadvantageous that a non-homogeneous distribution of the formaldehyde binding agents results, especially in a non-comminuted condition. This again causes an increased emission of the formaldehyde during production and further processing of the foam material to a detergent.
Further, a method is known wherein the formaldehyde content required for production is reduced in moist amino-plastic carrier materials for detergents by means of the combination of an additive solution with the formaldehyde catchers urea and sulfite.
With all known methods, it is a disadvantage that costly environmental measures are mandated for the production of a granular carrier material produced by grinding from foamed urea-formaldehyde resin foam because of the intense emissions of formaldehyde which occur in connection with this production.